Understanding camera lenses will give you the ability to have greater flexibility and control over your creative imagery.
When first starting out it can be daunting trying to understand which lens or lenses you should be purchasing. The kit lens that came with your camera will only go so far. Below I've listed some different types of lenses that you will come across and what their main purpose is. A small introduction to allow you to get the basic information on what that particular lens is actually created for.
Zoom Lens: A zoom lens allows you to get closer to your subject without the need of actually moving closer to it. It allows you to achieve a variety of different compositions in the quickest time. The focal length is measured in mm. i.e.: 70-200 is equal to 70mm to 200mm. This focal point is the key to the way the lens focuses. It magnifies the image by changing the focal point.
Prime Lens: Unlike the zoom lens, a prime lens has a fixed focal length which cannot be adjusted. Prime lenses are slightly quicker to focus with a much better level in picture quality as there are less moving parts within the lens itself.
Macro Lens: Macro lenses allow you to capture extreme close ups. They create a unique image of tiny subjects that cannot be seen with the naked eye.
Wide Angle Lens: This lens allows you to fit much more into an image than others, widening the amount of space that you can capture within the image. This lens is great when you have limited ability to step backwards to get more into an image or when shooting land and seascapes.
Fish Eye Lens: This is an oval shaped, 180 degree view of the world. Initially created to give the photographer the ability to capture whole skies and landscapes. A fun little lens that you can use creatively.
Telephoto Lens: High magnification lens enabling you to take long range action photography for the likes of sports and wildlife. It allows you to be further from the action and still capture in close shots. A monopod is usually used to stop camera shake on the images. Tripods: These are pretty straight forward. They hold the camera steady for long periods of time. It also give you the ability to take yourself into the image!
Monopod: The same basic functionality as the tripod with only one 'leg'. Much more convenient to carry around than a tripod, easier to carry and transport. Some places won't allow a tripod, like court-side at a sports match. They are often used in fashion and paparazzi images as well as they are easy to pick up and carry. Having only one leg means that you cannot simply let the camera sit on top of it and walk away, the main difference between the two.
Once you understand the purpose behind each of these items, it will allow you to get the correct ones for the purpose of your creative outlets, and remember, it is always better to shell out a little extra for the right lens instead of a new camera body. The better the glass, the better the image.